cant comment on the power as your link isn't working but ESAB are about the best of the best when it comes to welders and welding equipment. its basically what professionals use. usually their duty cycle information is on ther conservative side meaning they will take a lot more abuse than they are rated for.
i have a migtronic 160 and that will do 5mm plate if i v the edges of the plate so i would think the cheap easycraft chinese welder isnt actually producing the 145ams ist claiming to.
in terms of niceness to weld with the esab will feel and weld 1000times better than the easycraft.